Spending $40+K for a vehicle and looking to save about $2 on a tankful of gas.
I'm surprised you 87 octane users went for the $40+K.It must have hurt!
The manual recommends premium.Use it for best MPGs and performance.

 

I just took delivery of 2010RX350 2 weeks ago and was given full tank of gas, free by the dealer. the engine was knocking so badly that i thought something was wrong with it. i even took it back to the dealership and the service person said that it is just normal when the car is cold (i didn't think so for lexus). anyways, after driving down to almost empty tank, i filled it up with premium gas from esso. as i suspected, the knocking sound was gone with in couple of minutes and seems like car has lot more power than before. I dont know about the expert opinions but, i believe in common sense and practical more. just watch what dealer fills you up with.

 

Maybe that dealer's gasoline contains some of wrong additives.

Sounds like I have to carry the portable octane analyzer to sample my first tank of free gas.




I heard some dealers would do so, but I am quite surprised one of Lexus does it.

 

I have a question on Premium fuel for the hybrid Rx450h. They have redesigned it using the Atkinson cycle which I have read is not suppose to efficiently use Premium fuel. I also saw on Toyota's website that the EPA mileage estimates were based on using 91 Premium fuel. So does anyone know the recommended fuel for the hybrid?

 

I had the same experience with the free tank of gas from my dealer. The engine was noticeably rougher and less powerful on that first tank than on the second (10% Ethanol 93 octane Sunoco).

I've seen two other luxury brand dealers fill up their cars with regular gas before a test drive (Audi, Benz), I would not be surprised that Lexus does the same.

That being said, my engine is slightly noiser and has more vibration when it is cold, even with the nice stuff. When it's warm, it's very smooth and idles nearly vibration-free at the steering wheel.

 

Fatrocky: Is there another dealer that is near you because I would not take a car back to one that lie to me or try to save a few dollars by putting cheap gas in a new car when Lexus has paid the dealer to put premium gas in this car or you have in the dealer prep price of that new car.

 

billy44bo
This is the only game in the town of 700k people. so no choice of menu.

 

It seems New York state also has 10% Ethanol on all 3 type of octane gasoline

 

Most likely, the gas was old in the tank - and had saltwater in it. They don't fill the tank up for the trip across the ocean, and if the vehicle sits on the port for a while, condensation settles in the tank as it isn't pressurized when it hasn't been run in a while. They use gas stabilizers so the gas doesn't go bad in case it takes over a month before they fill it, but that only goes so far. Also, if the dealers reuse gas they drain from tanks (easy way to save cash), you are getting some really old, nasty gas. Terrible (and I believe illegal in most parts, if not all, of the country) business practice, but easy way for them to save $10.

 

Just use what is required, otherwise you're just pouring money down the drain.

Car and Driver article on premium gas

 

As for as i know almost all of the gas in my town comes from refineries in Alberta and Saskatchewan. so there is no long trip. the car is also made in Ontario and it just came 5 days before i took the delivery (i had to wait 4 weeks after deposit was given). The car that i purchase from is an auto mall where almost every brand is being sold and i think most of the dealerships in that mall are owned by one group. therefore they sell lots of cars from one place. there are only two gas stations near by to supply gas to the large quantity of cars(because every new car is being sold now a days, gets a full tank of gas). i thought it was saving of about $7.00 Canadian on a full tank of case between premium and regular. the first tank gave me 415kms with 61 liters of gas with 70% city and 30% highway driving. I will post the results with premium 91 octane Esso gas after i run down, even though the second tank of premium gas still has about 12 to 14 liters old gas left in it.

 

In Florida, we have 10% ethanol statewide in all grades.

 

Most of the metro area require 10% ethanol in all their gas for pollution control. Ethanol replace MTBE. Ethanol in gas actually makes the gas less efflicent and decrase gas mileage by 5% or so. Like I said earlier, the RX is one of those cars that, in theory, should be able to run on 87 or 91 octane gas because the compression ratio is borderline. With the LS, GS and the IS350 or Is-F, one should use premium only.

 

If we're not talking about premium/non-premium on RX and we only discuss the benefit of Ethanol, Ethanol has more environmental advantage than Petrol. IMO.

 

I think I am going to use premium. Why buy such a nice machine and fill it with a lesser grade. For those of you that want to take advantage of ethanol, I understand. Here in Oregon, all grades of gas have 10% ethanol.